Method of setting hydraulic packers



May 2, 1967 A. W. SMITH METHOD OF SETTING HYDRAULIC PACKERS Filed July 1S, 1964 2 Sheets-Sheet l Arf/nn* W J/77/ 299 INVENTOR May 2, 1967 A. w. SMITH METHOD OF SETTING HYDRAULIC PACKERS Filed July 16, 1964 VV. J/w/ INVENTOR.

BYZMZ afw- United States Patent O 3,316,969 METHD F SETTING HYDRAULIC PACKERS Arthur W. Smith, Houston, TeX., assigner to Big Three Welding Equipment Company, Houston, Tex, a corporation of Texas Filed July 16, 1964, Ser. No. 383,187 Claims. (Cl. 166-48) ABSTRACT 0F THE DISCLOSURE This invention pertains to the use of inert gas such as nitrogen, for setting hydraulic packers in petroleum and other wells.

A principal object of the invention is to provide methods for setting hydraulic packers in wells which are safe, dependable, and economical.

Another object of the invention is to provide methods for setting hydraulic packers in wells which provide for complete safety before, during, and after the time that the packers are set.

Hydraulic packer equipment employed in petroleum and other wells is of two general types. In one type, there is a packing ring surrounding a central mandrel which is energized, or set, by pressure applied thereto by an axially movable piston structure which is -actuated by hydraulic pressure applied within an enclosed space of the tool. The other general type apparatus employs a sleeve of elastomatic material which is inflated or blown up to force the sleeve outwardly against the structure with which the packer is to be sealingly engaged.

According to this invention, an inert gas, such as nitro- `gen gas, under pressure, is used to pressure the hydraulic fluid, usually a liquid, for setting the packers in the well. Heretofore it has been the practice to pressure up and set such hydraulic packer equipment entirely with liquid materials, such as oil, water, or the like. This procedure has certain disadvantages. It will be apparent that where oil or water is used, it will in most cases have to be removed from the tubing and casing equipment in the well before production from the well may be obtained. This generally necessitates `a swabbing operation, which is time consuming and expensive, and which at times results in damage to the equipment in the well. By using the concept of setting the packers with an inert gas, according to this invention, the gases are removed simply by relieving pressure at the wellheads, and the inert gas flows from the well and leaves no residue in the well to cause later procedures to be necessary for cleaning or otherwise preparing the well for its intended service.

According to this invention, the Well is kept under control at all times. The wellhead equipment may be installed above the well before the packer apparatus is set and prior to displacing mud from the well, if desired. By using an inert gas to set the packers in the well, no weight of a hydraulic liquid in the well is exerted on the packers so that the positions `and stretch of the tubing string or strings is not inuenced by the setting of the packers. In the case of multiple completion wells, having plural packers at vertically spaced locations in the well, the nitrogen or other inert gas pressure may be employed to set the packers in any desired sequence, and to accomplish displacement of undesired liquids from the well. The invention may be employed in connection with any type of packer designed for setting by hydraulic liquid means, the inert gas being substituted for the liquid, with the result advantages, in carrying out the setting procedure.

of hydraulic packer r master valve 18 for controlling ICC Additional objects and advantages of the invention will appear `from the following detailed description of preferred methods according to the invention, reference being made to the accompanying drawings, of which:

FiGS. 1 and 2 illustrate the methods of the invention in connection with a schematically depicted packer of the type wherein a piston-like member exerts axial force against an elastomatic sealing ring to Acause lateral expansion and sealing thereof with the wall of a well bore or a casing, and,

FIG. l being a vertical cross sectional view, in schematic representation, of the packer in unset condition in the well, FIG. 1 also showing the wellhead equipment and inert gas equipment employed in practicing the invention, the lower portion of FIG. l being enlarged,

FIG. 2 is a partial enlarged vertical cross sectional view similar to FIG. 1 showing the packer in set condition;

FIGS. 3, 4 and 5 illustrate the methods according to the invention in connection with a hydraulic packer of the type wherein an expansible sleeve is set by inllating or ballooning the sleeve into contact with the well bore or with the interior of a casing,

FIG. 3 showing the packer in unset condition, in vertical cross sectional schematic view, and also showing the wellhead apparatus and inert gas apparatus useful in practice of the invention, the lower portion of FIG. 3 being enlarged,

FIG. 4 showing the packer of FIG. 3 in set condition, and

FiG. 5 showing the packer of FIGS. 3, 4 after release thereof from set condition.

Referring now first to FIGS. 1 and 2 of the drawings, there is shown a well, indicated generally by reference numeral 10, having therein a surface or conductor casing 11 and an intermediate concentric casing 12. The casing 12 continues to the lower part of the Well 12 which is of smaller diameter than the upper portion of the well hole, and which is shown enlarged at the lower portion of FIG. 1. The outer casing 11 terminates downwardly above the lower end of the well. A tubing string 13 is shown disposed concentrically within casing 12. A casing head 15 is mounted above ground level 16 at the upper end of casing 11, and a tubing head 17 is mounted above casing head 15. Also shown in FIG. 1 are a flow through tubing string 13 in the well, and manifold 19 having lateral outlets 20, 21. An additional wellhead element 22 may be connected above manifold 19. The well head and casing and tubing equipment shown in FIGS. l and 2 is not intended to delimit the invention, but is shown only for the well equipment may take any other desired form.

A conduit 25 controlled by valve 26 extends from lateral outlet 2l of manifold 19 to an inert gas supply truck 27. Truck 27 is of the type for containing nitrogen in liquid form, and includes pumping apparatus and heater apparatus for converting the liquid nitrogen to high pressured gaseous form at the well site. The inert gas truck equipment is fully described in United States patent application Ser. No. 85,288, tiled Jan. 27, 1961, and now abandoned. However, other sources of high pressure inert gas may be substituted for the truck 27 and equipment mounted thereon.

At the lower enlarged part ot FIG. l of the drawings, the packer indicated generally by reference numeral 30 is shown disposed within the casing string 12. The packer may be at any point along the length of' casing string 12. The casing string and well are indicated as extending downwardly below packer 30. Upper member of packer Bil is connected at its upper end (not shown) to tubing string 13. Below its upper end, member 35 is outf, ri? ardly enlarged. The enlarged lower portion 36 of memer 35 is somewhat smaller than the interior of casing 12. r tubular mandrel 37 is screwed into member 35 at ireads 38. An L-shaped port 39 has spring-biased check alve 40 therein. The check valve is retained by threaded orted plug 41. Lower skirt portion 43 of member 35 urrounds a vertically movable annular piston 44 which las therearound spaced below its upper end O-ring seal 45, .nd which has an outwardly projecting flange 46 around ts lower end. Flange 46 engages the lower end of skirt i3 when the piston is in its uppermost position.

An O-ring seal 47 is disposed to seal between the upper :nd of mandrel 37 and the interior bore 35a of member 55. An L-shaped port 50 communicates between the ipaee above piston 44 and the bore 35a of member 35 be- :ween seal 47 and threads 38. An O-ring seal 52 seals between piston 43 and the exterior of mandrel 37. A ring 53 of elastomatic material, such as rubber, is bonded or otherwise connected at 54 at its upper end to the lower :nd of piston 44. The lower end of sealing ring 53 is similarly bonded or otherwise connected at 56 with the upper end of downwardly converging conical member 57. The conical outer surface 58 of member 57 engages the inner or back sides of a plurality of slip segments 60 circularly arranged around mandrel 37. Usually three or four slip segments are provided, although any number thereof may be employed.

The slip segments 60 are supported in circularly spaced notches 62 around the upper sleeve-like end of member 63 whcih is threadedly engaged to the lower end of mandrel 47 at threads 65. A lower tubular member 66 is threaded into the lower end of threads 65 as shown. Member 66 has secured therein by pin 67 a ball stop ring 68 having passage 69 therethrough. Member 66 may be connected at its lower end with additional sections of tubing string 13, which may continue as desired below the packer equipment.

In carrying out the methods according to this invention, high pressure nitrogen or other inert gas is passed downwardly through bore 35a of tubing string 13 and member 35. A setting ball 72 is dropped into tubing string 13 to come to rest upon ball stop ring 68 closing passage 69 prior to the introduction of the inert gas for setting the packer. A quantity of liquid 73 is usually, but not always, placed or left adjacent the packer in bore 35a to serve as hydraulic fluid for packer operation. However, inert gas may be passed downwardly through the packer prior to the introduction of ball 72 for purposes such as purging the well of undesired drilling fluid or the like, and for adjusting liquid levels of materials in the well. With ball 72 in place as shown in FIG. 2, the pressured inert gas in bore 35a pressures the hydraulic uid 73 which enters port 39 unseating valve 40 and acts against the upper end of piston 44 to move piston 44 downwardly within member 35. This piston movement initially causes conical member 57 to move downward to urge slip segments 60 outwardly to engagement with the interior of casing 12. In case it is desired to pack oit at a location in the well bore where there is no casing, the slip segments 60 will engage with the bore wall of the well hole. Then, after the slip segments 60 have engaged the interior of casing 12, to connect the packer assembly firmly in place in the well, the further travel of piston 44 downwardly acts to compress sealing ring 53 to cause it to expand outwardly as shown in FIG. 2 to sealingly engage the interior of casing 12. Ball valve 40 prevents escape of lluid from above piston 44 so that, once set, the packer remains in set condition, When it is desired to unset the packer, tubing string 13 and member 35 are rotated to unscrew threads 3S sufliciently so that the upper end of port 50 is above the upper end of mandrel 37. This releases pressure above piston 44 and enables piston 44 to rise within member 35 to relieve the vertical pressure on sealing ring 53 and to release the outward pressure on slip segments 60 to permit them to be moved axially of casing 12.

Removal of ball 72 may be accomplished by dropping a weight or wire line tool down tubing string 13 to shear pin 67 thereby removing the ball and ball stop ring from the tubing ow passage. weight plastic ball which may be floated to surface by release of gas pressure within the interior of tubing 13, member 35, and mandrel 37.

Referring now to FIGS. 3, 4 and 5 of the drawings, the casings 11, 12, tubing 13, and the wellhead equipment, the truck 27 equipment and its connection to the wellhead, are the same as shown in FIGS. 1 and 2 and are indicated by the same reference numerals. Again, the lower portion of FIG. 3 is shown enlarged, and FIGS. 4 and 5 depict the equipment enlarged as in the lower portion of FIG. 3.

In the packer apparatus shown in FIGS. 3, 4 and 5 to further illustrate the methods provided according to the invention, a tubular mandrel extends longitudinally and concentrically within casing 12. The upper end of mandrel 80 (not shown) is connected to the lower end of tubing string 13 by a suitable coupling. Mandrel 80 provides a continuation of tubing string 13. Additional sections of tubing string 13 may be connected to the lower end of mandrel 80. An upper packer head member 81 having conically tapered upper surface 82 has a cylindrical opening vertically therethrough through which mandrel 80 extends and is connected to mandrel 80 by a shear pin 84. Pin 84 extends into suitable perforations of mandrel 80 and member 81. A pair of vertically spaced O-ring seal means 86, 87 surrounds the interior of head 81 in suitable grooves provided therein to seal between head 81 and the exterior of mandrel 80. Spaced between these two seals there is an annular recess or groove 88 around the interior of head member 81.

A plurality of perforations 89 through the wall of mandrel 80 are positioned for Huid liow communication between the interior of mandrel 80 and groove 88. An L-shaped port 91 communicates with groove 88 and the upper end of an enlarged bore portion 92 at the lower end of head member 81. Port 91 has therein a springbiased check valve 93 which is biased by the spring to be closed to upward flow-through port 91. Suitably secured around a recess 94 around the lower end of head member 81 there is a cylindrical tubular sleeve 97 of elastomatic imperforate material, such as rubber. The lower end of sleeve 97 is similarly secured to lower packer head member 98 in a recess 99 around the upper end of head member 98. Mandrel 80 is fitted through a bore of head 98 and there is an enlarged counterbore 101 at the upper end of this bore. An O-ring seal 103 in a suitable groove around the interior of the head 98 bore seals between the exterior of mandrel 80 and the interior of head 98.

Below the lower end of head 98 in its position shown in FIG. 3 of the drawings, mandrel 80 has around its periphery circularly spaced longitudinal exterior grooves 106 which extend for a length at least somewhat greater than the thickness ofthe portion of head 98 below counterbore 101. A ball stop ring having a tlow port 108 therethrough is pinned by a shear pin 110 snugly received in perforations of mandrel 80 and ring 107. Therebelow mandrel 80 is outwardly enlarged at 111 to prevent the possible sliding of head member 98 off of mandrel 80 and to enable lifting of the packer from the well after use.

The packer, as shown in FIG. 3, is in condition for running into the Well with the tubing string 13. The outer dimensions of the packer are such that there is sucient clearance with the interior of casing 12 that the packer may be easily run into the well.

To set the packer according to the invention, a setting ball which serves as a fluid flow check valve is dropped into the upper end of tubing 13 and comes to rest on ball stop ring 107. This effectively closes the lower end of mandrel 80 against fluid ow downwardly therethrough. A quantity of liquid 173 is usually left or placed in the pipe string adjacent the packer as before to serve At times, ball 72 may be alight Y as hydraulic uid at the packer. Next, truck 27 delivers high pressure nitrogen gas through conduit 25, valve 26 being opened, and through manifold 19, master valve 18, and thence downwardly through tubing string 13. The pressured gas forces the liuid to enter groove 88 through perforations 89 and to flow past check valve 93 in port 91 to enter the interior of sleeve 97. The pressure iills or inflates sleeve 97 so that it securely and sealingly engages the interior of casing 12, or the inner bore wall of the well in case there is no casing therein, to close the well annulus around tubing string 13 against fluid flow therepast. During this operation, there is absolutely no danger of explosions or fires in the well or in the equipment around the wellhead because the inert gas is noninammable and will not support combustion of other ammable materials which may be present.

When it is desired to remove the packer from the well, upward movement of tubing string 13 and mandrel 80, pin 84 being sheared, causes movement of longitudinal grooves 106 to bridge across lower end member 98 of the packer. The remainder of the packer does not move upwardly with mandrel 80, and the pin 84 is consequently sheared, because of the engagement of sleeve 97 with the well bore. The iluid pressure inllating sleeve 97 is thus bled off or relieved past lower head member 98 through the longitudinal grooves 106 so that the packer is deated for removal. This condition of the packer is shown in FIG. of the drawings. The packer may be removed by further upward movement of tubing string 13 and mandrel 80 which will cause the enlarged lower end 111 of mandrel 80 to engage the lower end of the packer so that the packer will be pulled upwardly out of the well with the tubing string.

It is readily seen that the use of inert gas for setting of either type of packer results in a condition in the well whereby swabbing of the well after setting of the packer is entirely avoided. Also, by use of the inert gas, the well may be competely displaced either before or after the packer is run in or at any time before or after the packer is set. After the packer has been set, the well may be brought in by bleeding the nitrogen olf under surface choke control.

The method may be employed with single completion or with dual or other multiple -completion assemblies in the well. In the case of single completions, the packer is made up on the bottom of the tubing string and the tubing is run until the packer is at the `desired depth in the Well. With the packer in position and the tubing properly hung in the tubing hanger, the Christmas tree is then installed. The tubing and casing can then be displaced and the packer set as desired.

One exemplary method of displacing a single completion well and setting the packer with the use of nitrogen gas is as follows: Sufficient displacing fluid is pumped into the tubing to displace the drilling mud from the well to the desired extent. Next, the displacing fluid is displaced with pressured nitrogen gas injected down the tubing to a predetermined desired depth. Next, the ball is dropped into the tubing to seat on the ball stop ring and the tubing is pressured up with nitrogen gas to set the packer. Next, the casing may be pressured up with nitrogen gas to test the packer. The setting of the packer is then complete and the well can be brought in by bleeding oli the nitrogen gas from the tubing by a choke control installed at the wellhead at the surface.

For employing the invention in connection with a dual completion parallel string well, to exemplify -the methods, 'a single packer is made up on the lower end of a first string of tubing and run into the well to a depth to give a desired spacing between the single and dual packers. Then the dual packer, with a safety joint on the bottom (which may be omitted, if desired) is installed on the rst tubing string. Then the first tubing string is run to a deeper depth into the well to carry the single and double packers into the well to the proper elevations in the well. Then the second string of tubing is run into the well, spaced out and latched into the second opening of the dual packer and hung in a tubing hanger. In case it is desired to run the two strings of tubing simultaneously, a safety joint is incorporated in the second string. After the packers are in the desired position in the well, and both tubing strings have been properly hung at the tubing head, the christmas tree assembly is installed above the tubing head. With the equipment in this condition, the tubing and casing can now be displaced and the packer set as desired.

First, sufficient fluid is pumped into the first string of tubing to displace the casing to between the single and dual packers. Then the fluid is displaced down to a predetermined depth with pressured nitrogen gas. Next, the ball is dropped into the tubing which extends Ito the lower single packer and the packer is set with pressured nitrogen gas. Next, pressure is applied interiorly of the casing to test the single packer. Thereafter, the set-ting ball may be floated back to the surface by bleeding oilD the nitrogen gas pressure under choke control at the surface.

Next, suilicient fluid is pumped into the second string of tubing to displace the casing to a level -above the dual packer. Then the fluid is displaced to a predetermined depth with pressured nitrogen gas, the setting ball dropped into the tubing string, and nitrogen pressure applied above the setting ball to set the dual packer. Then the casing is again pressured with nitrogen gas to test the dual pressure. Thereafter, the setting ball is floated back to surface and the production zone brought in by lbleeding off nitrogen gas under choke control at the surface.

In the case of triple and other multiple completion wells, the procedure is analogous. The tubings and casings are displaced using nitrogen gas and the packers are set as has been heretofore described by application of pressured nitrogen gas.

The methods according to the invention may be employed with any type of well equipment used in conjunction with the hydraulically set packers. As has been stated before, the invention provides for efficient setting of the packers and simplifies the other procedures necessary in completion of a well. There is no hazard of fire because of the presence of nitrogen gas which will not support combustion. Swabbing of the well before or after the packers are set is avoided since the nitrogen gas is used to displace unwanted fluids in the well and may be removed simply by releasing pressure at the Wellhead. This pressure release can frequently 'be used to bring in the well.

While preferred embodiments of the invention have been shown and described, many modifications thereof may be made by a person skilled in .the art without departing from the spirit of the invention, and it is intended to protect by Letters Patent all forms of the invention falling within the scope of the following claims:

I claim:

1. Method for setting hydraulic packers, comprising running a hydraulic packer into a well in assembly with a well pipe, introducing fluid into the well pipe to at least partially displace liquids from the well pipe and from spaces in the well surrounding the well pipe, closing the well pipe beneath the packer, and introducing pressured inert gas into the well pipe above :the closure to set the packer hydraulically.

2. Method of claim 1, said inert gas being nitrogen.

3. Method of claim 1, said hydraulic packer being of the axially movable piston type, said pressured inert gas axially moving the piston hydraulically to axially compress a packoif.

4. Method of claim 1, said hydraulic packer being of ythe inflatable type, said pressure entering an elastomeric packoff sleeve to inflate the sleeve.

5. Method of claim 1, including running additional hydraulic packer means into the well each in assembly with an additional well pipe, each relatively upper packer seal- 3,316,969 7 8 Y ngly receiving therethrough a well pipe in assembly with 3,028,915 4/ 1962 Jennings 166--187 ach relatively lower packer, and displacing each well 3,142,338 7 1964 Brown 166--120 lipe and setting each packer as described.

References Cited by the Examiner CHARLES E. OCONNELL, Primary Examiner.

UNITED STATES PATENTS 5 I AMES A. LEPPINK, Examiner'.

2,935,615 5/1960 True 166-187 

1. METHOD FOR SETTING HYDRAULIC PACKERS, COMPRISING RUNNING A HYDRAULIC PACKER INTO A WELL IN ASSEMBLY WITH A WELL PIPE, INTRODUCING FLUID INTO THE WELL PIPE TO AT LEAST PARTIALLY DISPLACE LIQUIDS FROM THE WELL PIPE AND FROM SPACES IN THE WELL SURROUNDING THE WELL PIPE, CLOSING THE WELL PIPE BENEATH THE PACKER, AND INTRODUCING PRESSURED INERT GAS INTO THE WELL PIPE ABOVE THE CLOSURE TO SET THE PACKER HYDRAULICALLY. 